This invention relates to a time-setting device for an electronic watch.
The term "time" used herein is intended to represent not only the divisions of the day such as seconds, minutes and hours but also days changing monthly and weekly and the corresponding dates.
An electronic watch is generally designed to carry out the counting operation for tracing momentarily changing time by continuously supplying a time-counting circuit coupled to a time display device and comprising as many cascaded counter stages of the later described construction as the required time display units on the display device with time counting pulses which have a frequency defined by the smallest time interval being displayed on the display device and which are obtained by frequency-dividing clock pulses having a predetermined very high accurate frequency, e.g. 32,768 Hz or 16,384 Hz, generated by a clock pulse oscillator such as a quartz oscillator, and to display the momentarily changing time on the display device. For example, the time-counting circuit comprises a second-counting stage for counting time-counting pulses at the rate of one pulse at the smallest time interval for example, per second and generating carry signals every sixty seconds or one minute, a minute-counting stage for counting the number of carry signals from the second-counting stage and producing carry signals every sixty minutes, and a hour-counting stage for counting the number of carry signals from the minute-counting stage.
A typical time-setting means for such an electronic watch may be considered as the type which continuously supplies a time-counting circuit of the above-mentioned construction with time-correcting pulses of considerably higher frequency than the time-counting pulses in place of ordinary time-counting pulses for tracing momentarily changing time. However, such a time-setting method is effective only for the purpose of setting time up to the order of seconds or minutes, but unavailable up to a higher order such as hours, days or dates, so that a very large number of time-correcting pulses and a long period are required for the time-setting operation.
With an electronic watch, it should be noted that minute correction of time up to the order of seconds or minutes is seldom required, since a clock pulse oscillator generally generates clock pulses having a predetermined very high accurate frequency.
In most cases, however, there is required a larger correction of time up to the order of hours, days or dates.
Therefore, the object of this invention is to provide a time-setting device for an electronic watch capable of correcting time indications on the watch as speedily as possible by a relatively simple operation regardless of the length of time required for correction.